Oil and gas separator



Dec. 17, 1963 R. CHAMBERS, JR 3,114,329

OIL AND GAS sEPARAToR File@ Dec. 28, 1960 3 Sheets-Sheet 1 s, JR.

INVENTOR AIToRNEs ROY CHAMBER .J 2 7 9 s m 7 /MT///"// /////W\/////////////////////////////////J` M7 u. n u u m United States Patent C) 3,114,329 @EL AND GAS SEPARATGR Roy Chambers, Jr., La Porte, Tex., assignor to California Research QGrporation, San Francisco, Calif., a corporation of Delaware Filed Dec. 28, 1960, Ser. No. 78,947 3 Claims. (Cl. 1193-203) The present invention relates to oil and gas separation and, more particularly, to an oil and gas separator adapted to be incorporated in the production tubing of an oil well. y

ln oil producing wells and particularly in deep production Wells where oil is pumped to the surface, a problem is often encountered with gas commonly associated with the oil in the producing formation. There is usually a substantial decrease in pressure on the oil-gas mixture as it moves out of the oil-bearing formation into the production well. Hydrocarbon gas either in solution with the oil or in the free state expands as the oil enters the production borehole. if the gas is pumped with the oil to the suriace, serious dificulty is likely to be encountered with the pumping apparatus located near the producing formation. A positive displacement pump will act as a compressor of the gas and will lose much of its eiliciency in lifting oil to the surface. In severe cases, the pump may become gas locked as a result of pumping the gas, and damage to the pump may result.

Gas and oil separators have been utilized in order to remedy this problem. Generally, the gas and oil separator is a device which, by utilizing the different properties of the two substances, effects a separation of the oil and gas and allows them to be moved to the surface through dierent conduits. It is in this general area that the present invention finds its utility. lt should be noted, however, that the apparatus herein described is useful not only to separate oil and gas, but may also be used in separating any two fluid substances which have different specific gravities. Some examples of situations other than gas and oil separations where the apparatus may be used effectively include separating a water and oil mixture and separating a gas and water mixture. Therefore, the apparatus, although described herein primarily as a gas and oil separator, may be used to perform similar operations with no substantial alteration of the apparatus itself.

Briefly, the present invention provides for packing off a borehole with a production packer positioned in the annular space between a production liner and the production tubing immediately above a producing formation to form an upper and a lower chamber with the tubing through the packer being the only communication ther,.- between. A working cylinder is formed in the upper chamber adjacent the production packer by incorporating into the tubing there a specially prepared tubing member having a first lateral port for fluid flow between the interior of the working cylinder and the upper chamber and second lateral ports spaced above the iirst lateral port also for llow between the upper chamber and the interior of the working cylinder. A piston member comprising at least a pair of lands vertically spaced apart by a mandrel section having a central flow passage through at least part of its length is adapted to be inserted in the working cylinder to selectively bridge the first and second lateral ports to control the dow of uid between the lower and upper chambers. The piston member may be selectively positioned, so that the apparatus is adapted to separate oil and gas entering the upper chamber or it may be positioned so that well stimulation or a similar operation may be performed without removing the working cylinder from the borehole.

lt is a particular object of the present invention to provide an oil and gas separator to be incorporated into the production tubing of a producing well, said separator ice having a piston member adapted to be selectively positioned to control fluid flow from the producing formation, so that the separator may be selectively utilized to separate gas and oil or to act as a conduit for fluids used in well stimulation and similar operations without pulling the production tubing to remove the separator.

Further objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description and the accompanying drawings which are made a part of this specification.

ln the drawings:

FlG. 1A is a longitudinal View partially in section of the lower part of an embodiment of the invention positioned in a borehole.

FlG. 1B is a longitudinal View partially in section of the upper part of the same embodiment of the invention positioned in a borehole.

FlG. 2A is a longitudinal View partially in section showing the lower part of an alternative embodiment of the invention.

FIG. 2B is a longitudinal view partially in section showing the upper part of the same alternate embodiment of the invention.

FiG. 3A is a longitudinal view partially in section showing the lower part of an embodiment of the invention which provides for direct communication between the producing formation and the surface.

FiG. 3B is a longitudinal view partially in section showing the upper part of an embodiment of the invention which provides for direct communication between the producing formation and the surface.

Referring specifically to FiGS. 1A and 1B nwhere an embodiment of the invention is shown. A production packer '75l is paclted against the well casing 72 immediately above a producing formation to form an upper annular chamber 36 above the production packer and a lower chamber below the packer adjacent the producing formation (not ihov/n). The only communication therebetween is the tubing 94 through the inner bore of the packer 7h. Production fluids from the producing formation enter the lowerchamber and mixed gas and oil ilow up tubing 9d into the working cylinder Sil of the gas and oil separator. The working cylinder 5@ is attached to the packer itl by means of adapter sub 93 and collar 65. Devices adaptable for use as packer lll include, for instance, a standard production packer, a hook wall packer and a tubing anchor with scaling cups located below the anchor.

The Working cylinder 5l) is fabricated, for example, from an All seating nipple or from a piece of production tubing. The working cylinder is provided with one, or more, lower lateral ports 64 and upper lateral ports 36. These lateral ports give communication between the inner bore of working cylinder Sil and annular chamber 36. The upper end of working cylinder Sil is connected to the production tubing il? by collar d5. The production tubing lll continues to the surface.

Piston member 1.35 is inserted into the inner bore of working cylinder 5t?. The piston member 3.35 is attached to the base el of insert-type pump immediately below the standing valve d2. The piston member is composed of a pump hold-down 55 which shoulders on the upper end of working cylinder Sl?, a mandrel section 56 and a pair of lands at each end of mandrel 56 composed respectively of sealing cups S3, cup followers S4 and take-up nut 51; and sealing cups 57, cup followers 60, spacer 6l, lock nut 66, take-up nut 5g, and lock nut 58. Various arrangements of the components making up the lands will suggest themselves to those skilled in the art and those obvious modilioations may be employed within the spirit of the invention. lt is necessary that the lands form seals between the 'a u interior of the working cylinder and the exterior of the piston member 135 at their respective locations.

The mandrel section S6 of the piston member 135 has a central flow passage through only a portion of its length. The mandrel section 56 and the lower lands combine to prevent gas or oil from flowing up the interior of the working cylinder 50. Gas and oil instead iow through lower lateral port 64 through elbow 62 which is welded 63 to the exterior of working barrel 50 and then up iiow pipe 24 as indicated by arrow 19. Flow pipe 24 may be attached to elbow 62 by a suitable connection such as threads 68.

Flow pipe 24 is braced as necessary by bracing elements 22. Gas and oil continue up the flow pipe 24 as indicated by arrow 1G to the cap 26 of the flow pipe 24 where gas indicated by 14 flows to the surface in the annular space between production tubing 46 and casing 72 and oil indicated by arrow 12 falls back into the upper annular chamber 36. When the oil has reached the level of the upper lateral ports 3i) in the working cylinder 59 it ilows into the interior of the working cylinder 50 through upper lateral ports in the working cylinder 50 and ports 32 in mandrel section 56 from where it may be pumped to the surface.

Piston member 135 is attached to the base 41 of an insert-type pump. When the pump is pulled from the hole piston member 135 is pulled with the pump. Sealing cups 53 and 57 slide up the production tubing 4@ with the piston member 135. After the pump is pulled there is direct communication between the surface and the producing formation through production tubing The upper lateral ports 30 and the lower lateral port 64 need only be packed off to allow for well stimulation or a similar operation.

Referring to FIGS. 2A and 2B an alternate embodiment of the invention which incorporates a downhole choke or a similar attachment is shown. In this embodiment of the invention packer 7l) is set immediately above a producing formation to provide an upper annular charnber 36 between production tubing 4t) and casing 72 and a lower chamber (not shown) adjacent the producing formation. The only communication therebetween is tubing 94 which is connected to the working cylinder 59 by means of adapter sub 93, collar 74 and collar 65. The upper end of the working cylinder is connected to the production tubing 40 by collar 45. The working cylinder is provided with lower lateral port 64 and upper lateral ports 30.

Flow pipe 24 is in communication with the working cylinder by means of a suitable connection such as elbow 62 welded 63 to the working cylinder S0 at the lower lateral port 64. Flow pipe 24 provides for the tiow of gas and oil as indicated by arrow lil and should be long enough to rise above the level of oil accumulation in the upper annular chamber 36. As indicated by 14 gas lows up annular chamber 36 to the surface after emerging from the cap 20 on flow pipe 24 while the heavier oil falls back into the annular chamber 36 as indicated by arrow 12.

Piston member 136 is connected to the base 41 of an insert-type pump just below the standing valve 42. The path for oil ow through the pump is indicated by 43.

In this embodiment the piston member is provided with three pair of lands and two mandrel sections to bridge the upper lateral ports 35i and the lower lateral port 64. Oil and gas flowing from the producing formation through the tubing 94 in packer 7) must ilow through downhole choke 87 because of the seal formed by sealing cups 81, cup followers 82, spacer 83 and lock nuts S4 and 85 located on the lower end of mandrel section 90. The oil and gas are diverted through ports 67 in mandrel section 90 and then through the lower lateral port 64 in the working cylinder 50 into flow pipe 24 because of the solid section in mandrel 56 and the seal formed by sealing cups 122, cup followers 123, spacer 121, and lock nut 125.

The gas is flowed to the surface as described above and the oil is collected in annular chamber 36. When the level of the oil reaches upper annular ports 30 inthe working cylinder St? it ows to the interior of the working cylinder 5t) through ports 36 and ports 32 in mandrel section S6 from where it is pumped to the surface. The oil is directed to the interior of mandrel section 56 because the annular space between mandrel section S6 and the working cylinder Sii is sealed off by sealing cups 53, cup followers 54 and take-up nut 51 above upper lateral ports 3i) and by sealing cups 122, cup followers 123, spacer 121 and lock nut 12S below the upper lateral ports 36.

This embodiment of the invention has application in wells of relatively high bottom hole pressure where it iS desired to restrict production by maintaining a back pressure on the well. In some formations where there is an exceedingly high pressure, it is sometimes desirable to attach a conventional gas anchor in place of choke 37 to prevent the pressure from unseating the pump hold-down 55 from its seat on the top of working barrel 50.

Referring to FGS. 3A and 3B which illustrate the invention when the insert-type pump has been pulled from the hole and the lateral ports sealed off to provide for direct communication between the producing formation and the surface. A new piston member 137 is inserted into position in the working cylinder 50 to bridge upper lateral ports 3i) and lower lateral ports 64 in order to perform well stimulation or a similar operation or to allow for dow of both oil and gas to the surface. It is a particular advantage of the present invention that these operations may be performed without the necessity of pulling production tubing 4) to remove the separator from the tubing string.

The upper lateral ports 30 and the lower lateral ports 64 `are bridged by a mandrel section 100 extending through working cylinder 5t). The exterior of the mandrel section 1&0 is sealed with the inner bore of working cylinder 50 above the ports by sealing cups 102, cup followers 103, spacer 1116 and lock nut 137 and below the ports by sealing cups 112, cup followers 111, spacer 113, and lock nuts 114 and 115. A pump-out plug 116 may be incorporated in the piston member 137 to prevent plugging of the mandrel section 160 during insertion into the borehole. The plug 116 is removed by increasing the pressure on the plug 116 until pins 129 are sheared and the plug 116 slides out of the piston member 137.

Direct communication between the surface and the producing formation is now provided through the tubing 94 in packer 70, the interior of the mandrel section 160, the holes in pack-off seating coupling `161 and the interior of the production tubing 40.

The invention has been illustrated and described using particular pieces for fabrication. As is obvious to those skilled in the art, modications in equipment and arrangement may be made while still keeping within the spirit of the invention. All such modifications are meant to be included herein. The invention having been described, I claim:

l. Apparatus for controlling uid flow from a well to the earths surface, said well having a production liner therein comprising pack-ott means for packing oit the lower end of a production liner to form an upper chamber and a lower chamber, a production tubing extending through said pack-olf means as the only communication between said upper chamber and said lower chamber, an annular space above said pack-off means between said liner and said tubing, a working cylinder formed in said tubing, first port means in said working cylinder to form a fluid passageway from within said cylinder to the annular space between said tubing and said liner, said first port means being vertically spaced above said packolf means, second port means in said working cylinder to form a second fluid passageway between said working cylinder and said annular space, said second port means vertically spaced above said iirst port means, a movable piston member comprising a mandrel section, said section having a central flow passage through its entire length, and at least a pair or" lands vertically spaced apart on said mandrel section, and means for moving said piston member in said working cylinder so that the lands thereon may be positioned t0 bridge both said tirst port means and second port means to Iallow the uninterrupted flow of fluid from said lower chamber up said tubing.

2. In apparatus for controlling iluid ow from a well, said apparatus comprising pack-off means for packing off the lower end of said well to form an upper chamber in said well and a Klower chamber in said well, a production tubing extending through said pack-oil means, an annular space between said tubing and the wall of said upper chamber, rst port means in said 4tubing to form a uid passageway from within said tubing to the annular space between said tubing and the wall of said upper chamber, said rst port means vertically spaced above said packoff means, second port means in said tubing to form a fluid passageway from within said tubing to the annular space between said tubing and the wall of said upper chamber, said second port means vertically spaced above said rst port means, a rst piston member removably positionable in said tubing, said irst piston member com-` prising a mandrel section having a central flow passage through at least a part of its length and at least a pair of lands vertically spaced apart on said mandrel section, means for vertically moving said rst piston member so that the lands thereon may be positioned to bridge said second port means to control the flow of fluids between said lower chamber and said upper chamber and means for removing said 4rst piston member from said tubing; the improvement comprising a second piston member, said second piston member comprising a mandrel section having a central ow passage through its entire length and at least a pair of lands spaced apart on said mandrel section, and means for vertically moving said second piston member in said tubing in the absence of said rst piston member so that the lands thereon bridge both said rst port means and said second port means to establish uninterrupted uid communication through said tubing -to said llower chamber.

3. Apparatus for controlling fluid ow from a well comprising a production liner in a well, pack-01T means for packing off a portion of said production liner to form an upper chamber and a lower chamber in said liner, a production tubing extending through said pack-off means as the -only communication between said upper chamber and said lower chamber, an annular chamber formed by said production liner and said tubing above said pack-oft means, first port means -in said tubing to form a fluid passageway from within said tubing to the `annular space between said tubing and said liner, said first port means being vertically spaced above said pack-01T means, second port ine-ans in said tubing to provide a uid flow path between the interior of said ltubing `and said annular space, said second port means positioned above said rst por-t means, a removable piston member removably insertable in said tubing, said removable piston member comprising a mandrel section and at least -a pair of lands vertically spaced apart on said mandrel section, said section having a central flow passage through a part of `its length, means for vertically moving said removable piston member in said tubing so tha-t the lands thereon may be positioned to bridge said second lateral port means, means for removing said removable piston member from said production tubing, a second piston member insertable in said tubing, said second piston member comprising a mandrel section having a liow passage through its entire length and at least a pair of lands vertically spaced apart thereon, and means for vertically moving said second piston member in said tubing in the absence of said removable piston member so that the lands thereon may be positioned to bridge both said first port means and said second port means whereby direct fluid communication is established through said production tubing to the portion of said well below said production packer.

References Cited in the le of this patent UNITED STATES PATENTS 2,111,174 Cox Mar. 15, 1938 2,345,710 Lybyer Apr. 4, 1'944 2,652,000 Woolsey Sept. 15, 1953 2,652,130 'Ferguson Sept. l5, 1953 2,883,940 Gibson Apr. 28, 1959 

1. APPARATUS FOR CONTROLLING FLUID FLOW FROM A WELL TO THE EARTH''S SURFACE, SAID WELL HAVING A PRODUCTION LINER THEREIN COMPRISING PACK-OFF MEANS FOR PACKING OFF THE LOWER END OF A PRODUCTION LINER TO FORM AN UPPER CHAMBER AND A LOWER CHAMBER, A PRODUCTION TUBING EXTENDING THROUGH SAID PACK-OFF MEANS AS THE ONLY COMMUNICATION BETWEEN SAID UPPER CHAMBER AND SAID LOWER CHAMBER, AN ANNULAR SPACE ABOVE SAID PACK-OFF MEANS BETWEEN SAID LINER AND SAID TUBING, A WORKING CYLINDER FORMED IN SAID TUBING, FIRST PORT MEANS IN SAID WORKING CYLINDER TO FORM A FLUID PASSAGEWAY FROM WITHIN SAID CYLINDER TO THE ANNULAR SPACE BETWEEN SAID TUBING AND SAID LINER, SAID FIRST PORT MEANS BEING VERTICALLY SPACED ABOVE SAID PACKOFF MEANS, SECOND PORT MEANS IN SAID WORKING CYLINDER TO FORM A SECOND FLUID PASSAGEWAY BETWEEN SAID WORKING CYLINDER AND SAID ANNULAR SPACE, SAID SECOND PORT MEANS VERTICALLY SPACED ABOVE SAID FIRST PORT MEANS, A MOVABLE PISTON MEMBER COMPRISING A MANDREL SECTION, SAID SECTION HAVING A CENTRAL FLOW PASSAGE THROUGH ITS ENTIRE LENGTH, AND AT LEAST A PAIR OF LANDS VERTICALLY SPACED APART ON SAID MANDREL SECTION, AND MEANS FOR MOVING SAID PISTON MEMBER IN SAID WORKING CYLINDER SO THAT THE LANDS THEREON MAY BE POSITIONED TO BRIDGE BOTH SAID FIRST PORT MEANS AND SECOND PORT MEANS TO ALLOW THE UNINTERRUPTED FLOW OF FLUID FROM SAID LOWER CHAMBER UP SAID TUBING. 